In case of SDH-deficient GISTs, chest X-ray is indicated to look for pulmonary chondromas (especially if SDHx-WT), and plasma/urine determination of metanephrines/catecholamines and PET-tracers 68Ga-DOTATATE, 18F-DOPA and 18F-FDA can be used for investigating paragangliomas [141]. This evidence concerns the gene SDHB and paraganglioma.